Diazotype layers having organic esters and nitriles containing an active methylene group as azo components



Patented May 8, 1951 DIAZOTYPE LAYERS HAVING ORGANIC ESTERS AND NITRILES CONTAINING AN ACTIVE METHYLENE GROUP AS AZO COMPONENTS William H. von Glahn, Loudonville, and Lester N. Stanley, Delmar, N. Y., assignors to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application August 6, 1947, Serial No. 766,874

4 Claims.

This invention relates to a diazotype process and more particularly to the use of organic esters and nitriles containing an active methylene group as the azo components in the light sensitive layer of adiazotype reproduction medium or in a developing solution for the exposed diazotype image.

In the reproduction of mechanical drawings, printed material, pictures or other originals to be copied, it is of particular advantage in many cases to make first an intermediate print or transition print on a transparent diazotype copying material by exposing the transparent sensitized diazotype material to actinic rays, such as ultraviolet light, by either the printing through or reflex process and then developing the diazotype material. The development of such diazotype prints may be carried out by any of the developing methods known to the art for develop,- ment of exposed diazotype materials. Thus, Where a two-component system is employed containing the azo component in the light sensitive layer with the diazo compound, development s effected by passing the exposeddiazotype through ammonia vapors, and where a one-component i system is employed which contains the diazo compound as the only dye component in the light-sensitive layer, the image is developed by treating the exposed diazotype with an alkaline solution containing the azo component by a dip-.

ping or fog spraying method. The image thus produced on the transparent intermediate ortra-nsition diazotype print can be used for reproduction of further diazotype prints of high contrast. If desired, they can also be used iorthe reproduction of the image on any suitable photo-. printing material such as silver halide photographic paper and Van ljyke prints and blue prints.

This method of producing transition diazotype prints is particularly useful when it is desired to make a number of reproductions from a frail or valuable original which would be adverse.- ly afiected, if not destroyed, in the repeatedexposures necessary to make the desired number-of copies. It is essential in the so-called. reflex process, where the diazotype copy material is superimposed on the opaque original to be copied and the light for exposure of the diazotype matee rial passes through it and is reflected by the surface of the original. The eliiciency of the process involving the production of a transition or intermediate print depends upon the opacity of the azo dye image produced upon such intermediate or transition print to ultraviolet light and upon the transparency of the background to such light. It depends also upon the visual density of the image produced on the intermediate or transition print since images of poor visual density, such as light yellows on a white or transparent background, though they may have the desired degree of opacity to ultraviolet light, nevertheless have the disadvantagesof rendering difficult the detection of flaws in the intermediate image. With such prints, it is necessary to make a contrast print of good visualdensity from the intermediate before such flaws can be detected, there-. by introducing an additional and unnecessary step.

Prints of a deep color having good visual density can be obtained from diazotypes using aze components common to the art forthe production of ordinary diazotypes, such as phloroglucin, 2,3: dihydroxynaphthalene, and fl-naphthol-tfi-disulfonic acid. However, despite the good visual density of the color reproducing the image. its actinic opacity or photographic density is not sufiicient to reproduce the image satisfactorily in subsequent copies. The azo dye component used for the production of transition print images must be such as to produce upon coupling with the diazo compound employed a color which will sufiiciently absorb the ultraviolet light incident upon it during exposure to prevent light-decomposition of the diazo compound .in'the areas to be reproduced from the transition copies. Colors of good visual density do not necessarily have this property. It is well known, for instance, that blues, such as are produced from. azo components like phloroglucim'are very poor in their ultraviolet absorption characteristics.

Azo components such as resorcinol have heretofore been employed in the production of diazo type prints in order to obtain color images hav-.- ing the necessary light absorption characteristics for transition printing. Resorcinol will reproduce the image on the transition print in a sepia or orange-brown color which has good opacity to ultraviolet light and has sufiicient depth of color or visual density to assure detection of printing flaws and the like in the 19. veloped intermediate print. Otherazo components have been suggested which will produce images of good opacity or covering power when used in combination with polyhydroxy azo components, such as phloroglucinol and resorcinol. These azo p nts are acetoacet l deri at ves of mono-amines and are disclosed in Patent #1,989,065. However, although these acetoacetyl derivatives of mono-amines may produce when used as self colors, that is, when the 5 acetoacetyl derivatives of mono-amines, such as the cyclohexyl acetoacetic acid amide and the like disclosed in Patent #1,989,065, are used as the only azo components for the development of a diazoty pe print, the image produced does not have a satisfactory shade or tone value.

It has now been found that certain organic esters and nitriles containing an active methylene group are especially effective as azo components for diazotype reproductions. These organic esters and nitriles containing active methylene groups may be represented by the formula wherein R is a radical of the group consisting of acyl, carbalkoxy, nitrile and carbiminolalkoxy radicals and R is a member of the group consisting of alkoxy, carbalkoxy, aryl and heterocyclic radicals. The azo components of this class can be used satisfactorily either alone in the production of self-shades or in combination with other azo components for shading purposes. In either "case, the resulting images will have excellent properties of opacity to ultraviolet light and covering power. When used for shading purposes in combination with such azo components as phloroglucinol, 2,3-dihydroxynaphthalene or 2,3-dihydroxynaphthalene sulfonic acid, excellent neutral blacks having improved opacity to ultraesters and nitriles having active methylene groups of this class are l. Ethyl acetoacetate o en -(Lorneo-oc n Methyl acetoacetate o cm-t-oHzoo-oom Sodium ethyl oxalacetate 0 N ooton,o o-oo n Ethyl malonatc HsCzOOC-CHzCWOCzI-Is Ethyl benzoylacetate C6H5COCH2COOC2H5 12. Cyanacetylcoumarone 13. l-cyanaceto-2-naphthol methyl ether o o CHQCN OCH 14. 2-cyanaceto-3-oxythionaphthene ono oomoN s 15. Ethyl (p-ethoxy-p-imino) propionate 021150 COH2C o-o 02m In the preparation of diazotype materials intended for use as intermediate or transition print media in accordance with this invention, a suitable transparent base, such as transparentized paper, cellulose acetate film or other transparent material, is coated by means known to the art with a light sensitive composition containing suitable diazo compounds. Where it is desired to make a two-component diazotype layer on violet light are obtained Examples of or anic 35 the Support or base material for development by the dry developing method, the azo component is also incorporated into the coating composition. Where one-component diazotype layers are desired, the azo component is added to an alkaline developing solution and after exposure of the diazotype the exposed image is developed by contacting with the alkaline developing solution by means known to the art. In the preparation of coating compositions for two-component diazotype layers, the coating solution may also contain such other materials as are ordinarily used in the preparation of diazotype two-component light sensitive coating compositions. These include stabilizing materials, such as citric acid, phosphoric acid and thiourea; swelling agents for cellulose acetate and other cellulosic ester bases, such as isopropanol, and shade intensifying agents, such as nickel sulfate. In the preparation of light sensitive layers on paper for the production of neutral black images or dark tone images which may or may not be intended for reproduction of further copies, it is preferable to employ a two-component coating composition which will contain one or more dark tone producing azo components, preferably such as will produce blue shades with the diazo compounds employed in combination with the organic ester and nitrile azo components having active methylene groups of this invention. The diazo compound or compounds and other adjuvants are added to the coating composition and the paper used as a carrier for the light sensitive layer is coated in the same manner as the transparentized paper or cellulosic film base material in the case of the transition print media. As diazo compounds, any suitable light sensitive diazo compound which will couple with the azo components to reproduce a colored image, may be employed. We prefer, however, to use diazo compounds derived from p-diamines of the benzene series, particularly .when two-component coating compositions are employed. As is well known in the art, this class of diazo compounds is especially suitable for the production of two-component diazotype photosensitized papers. Other diazo compounds have been found suitable for use, such as diazo anhydrides of aminohydroxynaphthalene compounds, but areless extensively employed. The p-diamines most generally used for production of the diazo compounds are those wherein one of the amino groups is unsubstituted for diazotization and the other is substituted by such groups as alkyl, alkoxy-alkyl, aryl, aralkyl, alkylol, cycloaliphatic and heterocyclic groups. Examples of these amines from which the diazo compounds are derived include N-hydroxyethylN-methylamino-p-aminobenzene; pamino diphenylamine; 1-mono-methylamino-2-. (or 3)-methyl-4-aminobenzene; l-N-hydroxyethyl-N-ethylamino- 3 -methyl-4-aminobenzene; 1 diethylamino-3-ethoxy 4 aminobenzene; 4- amino-l-benzoyl'amino-Z,5-diethoxybenzene; pamino-N-diethylaniline; 1-N,N-dihydroxyethylamino-3-chloro-4-aminobenzene; p amino N- ethyl-N-benzylaniline l-ethyli-aminobenzene 1 N hydroxyethyl-N-ethylamino-l-aminobenzene; p-phenylene diamine; 4-amino-N,N-dihydroxyethylaniline; p- (4 -ethoxyphenyl) -amino- 2,5-diethoxyaniline; l-N-ethylamino-Z-methyl- 4-aminobenzene; 1-dimethylamino-3-methoxy-4- aminobenzene; N,N-dimethylamino p aminobenzene; l-dimethylamino-Lmethyl 4 aminobenzene; p-aminophenyl morpholine and 2-' amino-1-naphthol-5-sulfonic acid. The diazo derivatives of these amines are used in the form of their stabilized salts, such as the ZnCl2, CdCl-z or SIlClz double salts, fluoro borates, aryl or alkyl sulfonates, and acid sulfates of the diazonium chloride.

The following specific examples will serve to illustrate further the invention, it being understood, however, that they are not intended to limit its scope. Unless otherwise stated, the parts are by weight.

Example 1 Transparentized paper is coated with a coating solution containing the following ingredients per 100 cc. of water containing 5% of alcohol:

3.2 grams ethyl acetoacetate 3.8 grams N methyl-N-hydroxyethyl-p-benzene diazonium chloride-znClz double salt 4 grams thiourea 8 grams citric acid 2 grams phosphoric acid 5 grams ZnClz The resulting coated paper or diazotype has excellent properties of opacity to ultraviolet light and good precoupling stability during prolonged Transparentized paper is coated with a-coating solution containing the following ingredients per 100 cc. of water containing 5% of alcohol:

3.2 grams ethyl acetoacetate 3.5 grams N-phenylamino-p-benzene diazonium acid sulfate 4 grams thiourea 8 grams citric acid 2 grams phosphoric acid 5 grams zinc chloride The resulting coated transparency has good precoupling stability during prolonged storage. After drying the coating and exposing to light under a positive and developing the image with ammonia fumes, a reproduction of the positive isobtaineol in a sepia color of deeper brown shade than that of Example 1. The dye image has good fade and Wash-fastness properties and excellent opacity to ultraviolet light. Therefore, it can be used as a transition print in the reproduction of further diazotype copies or other photoprint copies.

Example 3 Transparentized paper is coated with a coating solution containing the following ingredients per cc. of water containing 5% of alcohol:

3.1 grams methyl acetoacetate 3.5 grams N,N-diethylaminop-benzene diazonium chloride-ZnClz double salt 4 grams thiourea 8 grams citric acid 2 grams phosphoric acid 5 grams ZnClz The thus coated diazotype transparency is dried in the usual manner. It has good precoupling stability against prolonged storage. Upon exposing the coated surface to light under a positive and developing the image bycontacting with ammonia fumes, the image of the positive is reproduced in a brownish-black color on a clear, transparent background. The dye areas of this reproduction have satisfactory fade and Wash-fastness properties and excellent 'opacityto ultraviolet light. The reproduction, therefore, can be used as a transition or intermediate print for the reproduction of further diazotype copies or other photoprint copies.

Example 4 Transparentized-paper' is coated with a diazotype coating solution containing the following ingredients 'per 100 cc. of Water containing 5% of alcohol:

3.9 grams sodium ethyl oxalacetate 3.5 grams N,N-dimethylamino-p-benzene diazonium fihlOIldE-ZIlClz double salt 4 grams thiourea 8 grams citric acid 2 grams phosphoric acid 5 grams ZnCle The thus coated diazotype transparency is dried in the usual manner. It has good preccupli-ng stability against prolonged storage.' Upon exposure to light under a positive to be reproduced and'upon developing the exposed image by contacting with ammonia fumes, the image of the positive is reproduced in a brownish-black color which has good fade and wash-fastness properties and excellent opacity toultraviolet light. Therefore, it can be used as a transition or intermediate print for the reproduction of further diazotype or other photoprint copies. I I

Example Transparentized diazotype paper stock is coated with a coating solution containing the following ingredients per 100 cc. of water containing 5% of alcohol:

3.0 grams ethyl cyanacetate 3.5 grams 1- (N-ethylamino) -2-methyl-4-benzene diazonium chloride-ZnCh double salt 4 grams thiourea 8 grams citric acid 8 grams phosphoric acid 5 grams ZnClz The thus coated diazotype paper is dried in the usual manner. It has good precoupling stability against prolonged storage under adverse conditions. After exposing to light under an original to be reproduced, it is developed by contacting with ammonia fumes to an orange-sepia colored reproduction of the original. The dye areas of this reproduction have good fade and wash-fastness properties and excellent opacity to ultraviolet light. The reproduction, therefore, can be used for obtaining further diazotype or other photoprint copies by using the reproduction as an original or transition print copy.

Example 6 Diazotype transparentized paper stock is coated with a coating solution containing the following ingredients per 100 cc. of Water containing 5% of alcohol:

5 grams l-benzoylamino-2,5-diethoxy-4-benzene diazonium chloride-ZnClz double salt 3 grams ethyl cyanacetate 4 grams thiourea 8 grams citric acid 2 grams phosphoric acid 5 grams ZnClz The resulting coated paper, upon being dried in the usual manner, exhibits good precoupling stability against prolonged storage under adverse conditions.

After exposing the coated transparentized paper to light under an original to be reproduced, the image is developed by contacting with ammonia fumes to an orange-sepia positive print. This print has good fade and wash-fastness properties in the dye areas and also excellent opacity to ultraviolet light which enables it to be used as a transition print in the reproduction of further diazotype or other photoprint copies.

Example 7 Diazotype transparentized paper stock is coated with a coating solution containing the following ingredients per 100 cc. of water containing 5% of alcohol:

2.5 grams ethyl malonate 3.6 grams N-ethylamino p benzene diazonium ChlOIidG-CdClz double salt 4 grams thiourea 8 grams citric acid 2 grams phosphoric acid 5 grams ZnClz The resulting coated transparentized paper is dried in the usual manner and exhibits good precoupling stability against prolonged storage. After exposing the coated surface of transparentized paper to light under a positive original, the image of the latter is developed by contacting the exposed coated transparency to ammonia fumes. The image of the original will be reproduced in a yellow-sepia color which has good fade and wash-fastness properties and excellent opacity to ultraviolet light. Therefore, it can be used as a transition print in the reproduction of further diazotype or photoprint copies.

Examp le 8 A diazotype coating solution is prepared by mixing the following ingredients into cc. of a 5% aqueous solution of isopropanol:

1.5 grams ethyl acetoacetate 2.0 grams 2,3-dihydroxynaphthalene-6-sulfonic acid 0.1 gram 2,3-dihydroxynaphthalene 3.0 grams N,N-diethylamino-p-benzene diazoni-- um chloride-ZnClz double salt 5.0 grams ZnClz 10.0 grams citric acid 2.0 grams phosphoric acid 5.0 grams thiourea Upon coating transparentized diazotype paper stock with this coating solution and drying, a diazo type layer having excellent precoupling stability is obtained. On exposing this diazotype layer to light under a pattern and developing with ammonia fumes, a reproduction of the original is obtained in excellent black shades on a clear background. On using this coating on nontransparentized diazotype paper stock and drying by the usual diazotype procedure, a diamtype layer of the same excellent precoupling stability is obtained. On exposure of this layer under a pattern and development with ammonia fumes, a reproduction of the original is obtained in an excellent black against the white background.

Example 9 Transparentized diazotype paper stock is coated with a coating solution containing the following ingredients perlOD cc. of water containing 5% of alcohol:

3.5 grams ethylQS-ethoxy-fi-imino)propionate 3.8 grams N-ethyl-N-hydroxyethyl-p-benzene diazonium dhloride-znClz double salt 4.0 grams thiourea 8.0 grams citric acid 2.0 grams phosphoric acid 5.0 grams ZnClz The resulting coated diazotype paper has excellent properties of opacity to ultraviolet light and good precoupling stability during prolonged storage.

Upon exposing the coated transparency, which has been dried in the usual manner, to light under a pattern, design or picture to be reproduced and developing the image with ammonia fumes, a sepia colored positive print is obtained. The dye or color areas reproducing the image have good fade and wash-fastness properties and in view of their excellent opacity to ultraviolet light, the print can be used as a transition or intermediate print for the reproduction of further diazotype copies or other photo-reproductions.

Upon substituting the following combinations of coupling components and diazo compounds for the ethyMB-ethoxy-B-imino)propionate and the N-ethyl-N-hydroxyethyl p benzene diazonium chloride-ZnClz double salt of this example, diazotype materials having the same properties of good precoupling stability and which will also produce a sepia colored image having the same opacity to ultraviolet light and good fade and wash-fastness properties of the dye are obtained:

(1) 3.4 grams ethyl sodium acetone oxalate 3.8 grams N-methyl-N-hydroxyethyl-p-benzene diazonium chloride-ZnClZ double salt (2) 3.2 grams cyanmethylphenylketone 3.5 grams N,N-dimethylamino-p-benzene diazonium chloride-ZnClz double salt (3) 3.6 grams 2-w-cyanaceto3-oxythionaphthene 3.0 grams 1-(N-ethy1amino)-2 methyl 4- benzene diazonium chloride-ZnCla double salt We claim:

1. A diazotype photoprinting material comprising a light sensitive diazonium salt of a pdiamine of the benzene series and an azo component selected from the class consisting of organic esters and nitriles of the following formula RCH2COR' wherein R is a radical of the class consisting of acyl, carbalkoxy, nitrile and carbimino alkoxy radicals and R is a radical of the class consisting of alkoxy, carbalkoxy, aryl and heterocyclic radicals forming a linkage of the group consisting of keto and ester linkages.

'2. A diazotype photoprinting material comprising a light sensitive diazonium salt of a pdiamine of the benzene series and as an azo component ethyl acetoacetate having the structural formula 3. A diazotype photoprinting material comprising a light sensitive diazonium salt of a p- 10 diamine of the benzene series and as an azo component sodium ethyl oxalacetate having the structural formula 0 NaOOC OH COOC H 4. A diazotype photoprinting material comprising a light sensitive diazonium salt of a pdiamine of the benzene series and as an azo component ethyl cyanacetate having the structural formula CNCHzC'OOCzHs 7 WILLIAM H. VON GLAHN. LESTER N. STANLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,710,455 Langguth et al Apr. 23, 1929 1,943,377 Ellis Jan. 16, 1934 1,989,065 Schmidt et al Jan. 22, 1935 2,113,330 Mannes et a1 Apr. 5, 1938 2,115,394 Mannes et al Apr. 26, 1938 2,435,661 Glass et al Nov. 9, 1948 2,436,007 Kendall et a1 Feb. 17, 1948 FOREIGN PATENTS Number Country Date 478,933 Great Britain Jan. 24, 1938' 525,765 Great Britain Sept. 4, 1940 525,874 Great Britain Sept. 5, 1940 525,875 Great Britain Sept. 5, 1940 

1. A DIAZOTYPE PHOTOPRINTING MATERIAL COMPRISING A LIGHT SENSITIVE DIAZONIUM SALT OF A PDIAMINE OF THE BENZENE SERIES AND AN AZO COMPONENT SELECTED FROM THE GROUP CONSISTING OF ORGANIC ESTERS AND NITRILES OF THE FOLLOWING FORMULA 